The present invention relates to an assembly of two interconnected similar plastic planks and a framework, and more particularly to one in which the planks are firmly interconnected.
In recent years, instead of a tile roof, a series of interconnected similar plastic planks have been positioned and fastened onto rafters running from the peak of the roof to its eaves in a side by side manner so as to form a sheathing. Referring to FIG. 1, there are shown two interconnected conventional planks A' and B'. Each of the conventional planks A' and B' has a U-shaped side portion 1 and an inverted U-shaped side portion 2. Each of the U-shaped side portion 1 and the inverted U-shaped side portion 2 has an inwardly inclined end edge 11, 21 so that the inverted U-shaped side portion 2 of the plank A' is held on the U-shaped side portion 1 of the plank B'. When the planks are interconnected, a seal strip 3 is used to seal the U-shaped side portion 1 so as to provide a water-proof effect. In absence of the seal strip 3, such a assembly is not water-proof. In additon, it is easy for the two interconnected side portions 1 and 2 to loosen from each other. Furthermore, after the seal strip 3 is provided between the two interconnected planks A' and B', the assembly becomes unsightly.